The proposed meeting is scheduled for March 2004 and will take place at a hotel conference room to be rented for the purpose in Washington, DC. The proposed meeting is a follow-up to a small gathering hosted by CONRAD in March 2003. That event drew together those interested in detecting vaginal and cervical exposure to semen, particularly when barrier devices are used during intercourse. Our own primary interest in this field relates to predicting the effectiveness of barrier devices to protect women against pregnancy or sexually transmitted infections before investing in full-fledged clinical trials of effectiveness. The topic has applications also for measuring protocol compliance in trials of such devices (validating coital logs or other self-reports with biological evidence), for prosecuting rape cases, for evaluating ways to protect the cervix following cryotherapy or other trauma, and for understanding the mechanisms by which sperm and STI pathogens contact the cervix and possibly proceed into the upper genital tract. Goals: If they could be validated and agreed upon, markers of exposure to semen would be useful in assessing compliance in clinical trials of barrier contraceptives and STI preventatives. They would also be useful for prioritizing which devices should undergo costly and complicated field trials first, as well as for establishing equivalence between devices if and when the first devices prove efficacious in prospective trials. Finally, markers would be useful in assessing the degree of protection afforded the cervix by different ways of using the cervical barrier devices (fitted or not, worn for various lengths of time after intercourse, and the like). Types of participants: We plan to invite current forensic experts working in the field of sexual assault, clinical and social scientists active in studying barrier methods, and advocates and policy makers sharing these interests. Topics to be covered: We plan to review and critique the state of existing markers for exposure to semen (sperm, PSA, Y chromosomes and others) as well as methods for collecting appropriate samples, a particular challenge when working with diaphragms and cervical caps, since device removal disturbs the surfaces of interest before they can be sampled. We will also discuss new markers now under development, and new applications for existing and future markers.